oestriol vs estrogen

oestriol and estrogen both are nouns.

Word	Noun	Adjective	Verb	Adverb
oestriol	Yes	No	No	No
estrogen	Yes	No	No	No

As nouns, estrogen is a hypernym of oestriol; that is, estrogen is a word with a broader meaning than oestriol:

oestriol: a naturally occurring estrogenic hormone; a synthetic form is used to treat estrogen deficiency
estrogen: a general term for female steroid sex hormones that are secreted by the ovary and responsible for typical female sexual characteristics

Other hypernyms of oestriol include oestrogen.

oestriol (noun)	estrogen (noun)
a naturally occurring estrogenic hormone; a synthetic form is used to treat estrogen deficiency	a general term for female steroid sex hormones that are secreted by the ovary and responsible for typical female sexual characteristics